The country's defence chief warned that Duterte would not hesitate to impose martial law but insists it is a 'remote possibility'.

Philippines President Rodrigo Duterte is reportedly mulling over declaring a nationwide martial law if things spiral out of control, warned the country's defence chief. Though he admitted a nationwide measure was a "remote possibility", the firebrand president has not apparently ruled out the option.

Duterte had earlier clamped martial law in southern Mindanao region in late May after intense clashes erupted between Islamists and security forces. This allowed the Filipino government and armed forces to push extremists from the region.

Mentioning his recent conversation with Duterte, Lorenzana said: "He [Duterte] said, if the left will try to have a massive protest, start fires on the streets, they will disrupt the country, then I might [declare martial law]."

"In my opinion, in my estimate, the possibility of this happening is very remote. But the president is, indeed very concerned because it might get out of hand," added Lorenzana.

Asked about the situation, House Speaker Pantaleon Alvarez, one of Duterte's closest establishment figures, said on Friday that the scenario of a nationwide martial law is unlikely.

The outspoken president himself warned on 9 September that he would impose martial law if necessary. "Do not commit the mistake of staging a rebellion. I will not hesitate to impose martial law all throughout the country and order the arrest of everybody," Duterte said.

"You can have the city, but do not create trouble. Do not resort to destruction and trouble because I will order the military and the police to go against you," he warned the communist forces planning to hold demonstrations.

A masked anti-government protester takes part in a march towards the Philippine Congress ahead of President Rodrigo Duterte's State of the Nation addressErik De Castro/Reuters